Pickup trucks, trailers and vans have commonly been used to transport small sized wheeled vehicles such as all terrain vehicles, riding lawn mowers, small tractors and motorcycles. Although relatively small in size, these wheeled vehicles can weigh anywhere between 500 and 1,000 pounds and therefore cannot be easily lifted into the carrier vehicle. Typically, portable metal ramps have been employed to provide a way to easily load and unload these small sized wheel vehicles from the bed of pickup trucks or the cargo area of trailers and vans. During loading, the top end of the ramp is placed on the edge of the tailgate of the pickup truck or the loading end of the trailer or van and the bottom end rests on the ground. The all terrain vehicle, riding lawn mower, small tractor or motorcycle is then pushed or driven onto the ramp where it travels up the ramp and into the bed of the pickup truck or cargo area of the trailer or van. The ramp is then removed, stored in the carrier vehicle and the cargo is transported to another location where it is unloaded. During unloading, the top end of the ramp is again placed on the edge of the tailgate of the pickup truck or the loading end of the trailer or van and the bottom end rests on the ground. The all terrain vehicle, riding lawn mower, small tractor or motorcycle is then pushed or driven onto the ramp where it travels back down the ramp and comes to rest on the ground. The ramp may again be stored in the carrier vehicle for later use.
The ramps are typically either of a single hinged design having two ramp halves that fold upon each other for storage or comprise two separate ramps which are placed in parallel arrangement and at a specified distance from each other during use so that the ramps align with the wheel base of the three or four-wheeled vehicle being loaded or unloaded. The ramps are normally constructed of a light weight metal (e.g., aluminum) so that they can he conveniently handled by one person to load and unload the vehicle to be transported. Examples of portable ramps are described in the following patents:
U.S. Pat. No. 4,478,549 discloses a loading ramp having left and right rectangular ramp panels. At the top of each ramp panel section there is a pair of tailgate anchors which engage the tailgate of the truck, trailer or van when the ramp is operational. Flexible cables are attached to each ramp section to form a tension carrying removable connection extending between each ramp section and the truck, trailer or van during use. The left and right ramp panel sections are connected together by a hinge assembly at cooperating, abutting mating edges so that they can fold onto each other to reduce the ramp for storage.
U.S. Pat. No. 3,517,791 discloses a pair of ramps which may be used for loading and unloading cargo from trucks. The pair of ramps may be used separately to provide flexibility of use and may be used in a parallel engaged position to provide a wider ramp surface for handling wider cargo.
U.S. Pat. No. 5,730,577 discloses a motorcycle loading and unloading device including a ramp having a pair of spaced, parallel ramp rails. The ramp is adapted to be connected with a pair of bed rails that are carried on the bed of a truck or on the bed of a trailer.
Generally, the structural framework of the ramp includes two side beams and three or more cross beams which extend between the side beams. The ends of the cross beams are welded to the inner side wall of the respective side beams. To ensure structural stability, customarily the entire circumference around the end of each cross beam is welded to the inner side wall of the side beams. This process requires that the welding be accomplished from both the top side of the ramp and from the underside of the ramp in order to gain access to the entirety of the welding sites. Unfortunately, this welding process is time consuming and labor intensive. Not only are extensive and complete welds required at all connection points, but the ramp itself must be manipulated during the welding process to provide access to both the ramp's top side and underside. Hence, there exists a need to eliminate a portion of the welding at the cross beam/side beam connection points in order to manufacture a more economical ramp while still maintaining the structural integrity of the ramp.